Author: Anurag Sahay
Write digits into some cells so that each row and column contains exactly two digits. Numbers outside show the product of the digits in the corresponding row or column. Two cells with digits cannot share an edge and all cells without digits should form single orthogonality connected area.
Grid control: Click at a cell reveals the value chooser. Click at the selected value changes the state of the cell. More details about grid control are at the help page.